Ventilator



Aug. 19, 1952 I PURDY 2,607,280

VENTILATOR' Filed May 1, i946 INVEN TOR.

ATTORNEY.

Patented Aug. 19, 1952 A i I 'jaaacomsc v 1 -vEN'rILAtronfl Rolland'MfiPurdy; Bainbridge'N Y.; assi g BendixiAviation'ICorporation,N

acorporafidmbflnclaware V k V lA p'lilicatioiiMay. 1,1945;S1eria1iibibhi59 This invention relates to a'ventilator. 'The'in-'vention is adapted to'm'anyuses; but will be describedin particularrelation :to a small ventilator of thetype employed: to exhaust smallelectrical .machinery, it being understood that this particu-- lardescription isnot limitativebut is for'purposes of illustration only.

Two general'types of ventilator are-described in the prior art. Theearlier of these types" has a discharge pipe connecting the space thatis to be ventilated to a swinging head controlled by a wind vane thatturns the backof the ventilator to the wind which'draws' the air fromwithin the ventilator pipe in" passing. That' type of venti- "latorh'as'recognized faults; among which are'its' tendencies under certainconditions to admit. rainwater and to provide down drafts.

In order to' overcome" the. objections .to ventilators 'of the. swinginghead type, it has been proposed to use fixed ventilatorsihaving amaze ofbaffles. intended to permit unidirectional, .1 outward flow of air-only.For some'uses, thefixed type of ventilatoris superior 'totheiswinginghead i type, but the fixed .typeha's'its'faultS alsoqThe draft is not:alwa-ys.good,"'straycurrents appear to wander betweentheinnerandthe'outer chambers and to lower the 'efliciency ofthedeviceiand theexclusion of rain orother liquidsis notalways accomplishedwhen the: device is cemployed' in exposed positions;

It is an object of.this inventionto provide a stationary ventilator"with improved draft and decreased back draft p p I Another object .ofthe: inventionfisptq provide j a ventilator of improved design andconstruction which can be made, 'byiin ethods o'fferingthe greatestmanufacturing. advantages; in shapes adapted to produce "theimosteiiicient'results.

'Another object. of the "inventionis toaccom- *plish the objects of theinventionyby.atventilator I having-at leastthree.concentricslottedchambers,

the slots ofwhich' are other. 7

Another object 'offthe invention. is; to einploy the principles'of theVenturitube in a'fixedve'ntioffsetwith respect to each lator toincrease'the draft thereof.

' the following detailed descriptionwhenthe same is .read in' connection'with the,.ac'companying drawings. 'Itis'to'be understoodghowever, thatthedrawings are forthe purposeofillustration onlygarid are hniixihtendedasai'defifiition of the liimits-of"flahe inveritionkfreferencef -for-thislatter "purpose being had p'rima'rily t heappended *claims. 1 J

'*-plary 'venti-lator substafitiallyion th "line I- -l' of l-"Eig?2; 1

Fig. 2 is a crossrsectionsubst "'2-2ofFig:, 1; V

E'Fig? 3 is;an elevationaliview 'f' agvehtilatoi headc'onstrnctedriniaccordanoefwi the' principl'es-of ly' on'therline threetcapsor shellsthat are adapted to""- fit the head'of'Figfi-mnd. I

-section-through a Fig. 7 "is" a vertic'al' cross modifiedform oftheinvention.

""In' thepr'eferred Torinof the' inventiomwhich isidisclosed' inFigs; 1to '6",}.the'-numeralfl 0: indic 'cates in general" a" ventilator headwhich; has a screw threaded shank-1 l and n a'nnu-lar 'flange I2 uponwhichare j-iornie ie 'of annular steps I3, l t-15,16; rii hehead ter-'minatesshortbfthe connected'with "the discharge openings i8; which areshown' in this modificationto'b io ur in umber; normal to the bore andtothe openings ther side. The 'topofthe-head'is'prqvidedywr *"a shoulderl9 and'astud 20which*cqoperate tli-the annular steps to seat the capsjthat rem-"the chambers and produce median. p i The inner chamber-wliibh'is{designe dto receive' the discharge rromithebpemngs' 8 is formed by'the cap 2 l'-' which has centifalopeningthat fits the stud 20", asshown1n- Fig. and; is provided inits side With-'S 10t's' -22 that permi't'its gas con- 40 tent to' be drawn into th cap 23. The walls ofthe vvflsuclilength and diameter thatthey; re' p0 the step l5 and snugly fitthe "anniilar-side' of" the step" I 6 when the cap is seated upontheshoulder 19. "The intermediate cap 23*; iiimensidriallyjlarger but issimilarjtof the c A Xcept, that its" slits are provided with- Vou urn"extend'throu'ghoutth movin eas stpast'the' vantage because. it redp. Wp, thedischarge openingscause'd by vagrant gas ber formed by currents,and produces an improved and a steadier draft. The cap 23 preferably hasa snug fit to the top of cap 2|, the exterior of step'i5, and the top ofstep l4. In order'to complete the device and to produce therewithin amaximum draft, there is provided an outercap 25 which seats upon theledge l3 and snugly against'the annular faceof ledge [4. When the threecaps are in concentric position as shown in Fig. 1, the stud 20 may beheaded to provide a permanent uniting of the parts.

The outer shell has opening thereabout, a

least one of which is bound to receive air or other gas currents fromwhatever side the air blows, others of which serve as discharge portsfor such currents and for the gas exhausted through the ventilator head.The currents of gas are shown, in Fig. 2, to be coming from thedirection which, on a compass rose, would be northwest. They enterdirectly into that slot of the cap and are diverted as shown by thearrows toward the adjacent flanges in the intermediate cap 23. Theflanges extend toward the outer wall of the ventilator, reduce the areaof the passage which the gases follow, and produce a Venturi-efiectofincreased velocity and decreased pressure past the openings, therebyacting with increased efiect to exhaust the air from within the nextinner chamber. The exhausting and exhausted gases escape through thenext openings in the outer wall, as shown by the arrows.

The step. construction of the flange I2 is of great advantage inpreventing. the access of moisture to the interior of the ventilator andin maintaining drainage. However, the step construction need notnecessarily be employed.

The caps may be most simply made from flat blanks of suitable metal suchas aluminum; a satisfactory method includes stamping out and bending tothe required shape. The stamping of the intermediate cap shown in Fig.is preferably so executed as to produce in one'operation the flanges 24.The area of the openings in the succes sive caps preferably increasesoutwardly, to'p roduce the greatest draft. possible within the limitingsizeof the unit.

It is not necessary to permanently connect the caps to the head but theymay be temporarily connected thereto asshown in Fig. 7. In that figure,the ventilator head30 has a flange 35 with i only two steps SI, 32. pThe outer cap 33. is provided with slits 34 and encircles the flange 35,

preferably resting snugly thereagainst during operation. A cylindricalmember 35 having an annular flange 31 is emplaced within the member 33with the flange bearing against the inner surface thereofr Withinthe'member 36 is another cylindricalmember 38 having slits 39 and anannular flange 40 which rests upon the step 3!. The ventilator isassembled-by meansof a screw 42 which-is threaded into the upper portion.43. of the head 3 0. A washer and lock'washer are shown between the cap33 and' the head of thescrew. w

In Figs. 1 to 6 there are four openings or slits, such as at 22, in eachcap and four openings I 8 in the head l0. The openings 22 in the innercap are offset 45 from the discharge openings I 8, the

openings in the intermediate cap '23 are. offset 45 from those ofthezinner cap; andthe openings .of the outer cap are'ofiset 45,from'those of the intermediate cap. This arrangement-is automatically assuredby small studs 50, '5 i, 52 mountinexpensive to construct, easy toassemble and dismantle, and pleasing in appearance. They may be made insizes far smaller than that illustrated in the drawings and in verylarge sizes, and exhibit superior efiiciency in each size. They arepractically waterproof and are practically proof against back draftseven under the most adverse conditions.

Although only two embodiments of the present invention have beenillustrated and described in the accompanying drawings andspecification.

it is to be expressly understood that the invention is not limited tosaidembodiments. Various changes may be made therein, particularly inthe design and arrangement of the parts illustrated, and in the materialused, without departing from the spirit andscope of the invention, aswill now be apparentto those skilled in the art. For a definition of thelimits of the invention, reference is had primarily to the appendedclaims.

What is claimed is:.

l. A ventilator comprising an air discharge head having a bore, adischarge opening normal thereto, an axially arranged stud and a flangewith a series of annular steps, three concentric cylindrical capsaligned by the stud and conforming to the steps, slots dividing. saidcaps into sections, cooperable means on the head and caps to positionthesame and'circumferentially ofiset the slots in the intermediate capfrom those in the other caps, and out-turned flanges along the slotedges of the intermediate cap.

2. A ventilator comprising an air discharge head having a bore,discharge openings normal thereto, a stud at the end thereof and aflange with a series of annular steps, three concentric cylindrical capsconforming'to the steps and aligned by the stud, slots dividing saidcaps into quadrants, means on the flange to position the slots inadjacent caps at to each other, and

out-turned flanges along the slot edges of the intermediate cap.

3. A ventilator comprising a central discharge head having an axialbore'terminating intermediate its ends and port means connecting theinner end of the bore and the external surface of the head, an externalflange on said head, means comprising a plurality of cylinders seatedagainst said flange around said port means and forming the walls of aplurality of concentric annular chambers around a portion of said head,said port means being spaced from both ends ofthe innermost chamber andeachof said walls being axially slotted to connect adjacent chambers toeach other, the slots in each wall being circumferentially offset withrespect to the slots in adjacent walls, flange means on each of saidcylinders forming the end walls of said chambers opposite said headflange, means connected with said head and extendingcentrally throughandoperatively engagingpsaid flange means for securing said head andchamber forming means in fixed relation to each other, and. outwardlycurved flanges ,along necting said bore and the external surface of thehead, means comprising a plurality of concentric cylinders surroundingsaid port means and forming the walls of a plurality of concentricannular chambers around a portion of said head, said port means beingspaced from both ends of the innermost chamber and each of said wallsbeing axially slotted to connect adjacent chambers to each other,external flange means on said head forming an end wall of said chambers,internal flange means on at least one of said cylinders forming theother end Wall of said chambers, and means connected with said head forsecuring said internal flange means to the head.

5. A ventilator comprising a central discharge head having a bore anddischarge port means connecting said bore with the external atmosphere,external flange means on said head, means seated against saidflangemeans around said port means and forming a plurality of concentricannular chambers around a portion of said head, said last-namectmeansincluding radially spaced concentric side walls and internal flangemeans on at least one of said side walls forming the ends of saidchambers opposite said external flange means, and means extendingcentrally through said internal flange means for securing said internalflange means to said head, said port means being spaced from saidexternal flange means and said side walls having axially extending slotsfor connecting adjacent chambers.

6. A ventilator comprising a central discharge head having an axial boreand radially extending port means connecting said bore and the externalsurface of the head, means surrounding said port means and forming aplurality of concentric annular chambers around a portion of said head,said means comprising a plurality of concentric cylinders forming theside walls of said cham- 4 bers, and external flange means on said headand internal flange means on at least one of said cylinders forming theend walls of said chambers, said port means being spaced from saidexternal flange means, and means extending centrally through andconnecting said internal flange means to said head, said side wallshaving circumferentially spaced slots therein for connecting saidchambers, the slots in adjacent walls being circumferentially offsetwith respect to each other.

7. A ventilator as defined in claim 6 wherein outwardly curved flangesare provided along the edges of the slots in at least one of theintermediate side Walls.

8. A ventilator as defined in claim 6 wherein the surface of saidexternal flange means forming the end walls of said chambers has ageneral contour which is inclined to the longitudinal axis of said bore.V

9. A ventilator as defined in claim 8 wherein said head flange surfaceis stepped, the steps serving as pilots for said chamber forming means.

- ROLLAND M PURDY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

